Thermal barrier of insulating material and metal frame members



May 27, 1969 C. I. BRAGMAN THERMAL BARRIER OF INSULATING MATERIAL AND METAL FRAME MEMBERS Filed Feb. 13, 1967 'INVENTOR. Clifford I. Bragman BYZ ATTORNEY United States Patent O US. Cl. 52309 8 Claims ABSTRACT OF THE DISCLOSURE Described is a thermal barrier, useful as stock material for an insulated frame, particularly in dual primary windows. The thermal barrier is made by telescoping (FIG- URE 1) metallic (preferably aluminum) frame (10) over insulating block (12). Frame and block have been prefabricated, for example, by extrusion process. The block is provided with receiving openings (22L, R; also 21L, R) into which frame projections (20L, R; also 21L, R) fit, initially with clearance. The frame is fractured at its center (14) by action of a die or roller (16; FIGURE 2) and the frame projections are forced into their receiving openings with complete sealing.

This invention relates to insulated frame members, particularly frame members which may be integrated in frame structures in which the basic structural material is a metal, such as aluminum or steel. More particularly, the invention is directed to such frame members when used in conjunction with windows, curtain walls, store fronts or entrance doors.

In connection with uses mentioned in the preceding paragraph, conventional frame structures, owing to their good thermal conductivity, are subject to the undesirable effects of condensation and frosting, particularly if such structures are used in cold climates.

It is an object of the invention to provide an insulated frame member by the use of which the undesirable effects of condensation and frosting are substantially eliminated.

Another object of the invention is the provision of an insulated frame member, hereinafter also referred to as a thermal barrier, which, when integrated in the frame structure, will provide a completely insulated window or the like.

A feature of the invention described herein is provision of a relatively simple and inexpensive method of making the insulated frame members contemplated by the present invention, which method, insofar as is possible, draws on materials, equipment or techniques already in use in frame manufacturing, or on materials otherwise readily obtainable.

To facilitate understanding thereof and not by way of limitation, the manner in which the stated objectives are attained, and a brief statement of the invention, are given more conveniently with reference to the accompanying drawings in which:

FIGURES 1 and 2 are cross-sectional views, drawn essentially to scale, of a thermal barrier in accordance with a preferred embodiment of the invention, these figures respectively illustrating the thermal barrier before and after completion of its manufacture; and

FIGURES 3 and 4 are respectively front elevational and top plan views illustrative of an alternative method of making the device illustrated in FIGURES 1 and 2.

The objectives of the invention are realized, referring also primarily to FIGURE 2, by provision of a thermal barrier 13 which comprises an elongated member of thermally insulating material 12, and an elongated, relatively thin metallic frame-like member 10 which overfits the insulating member to substantial length of the latter and 3,445,974 Patented May 27, 1969 forms with it a unitary elongated body 13, said metallic member being split apart along the longitudinal direction of said unitary body, the arrangement being such, that considered in cross-section through said body, the frame member at least partially envelops the periphery of the insulating member with each free end 20L, 20R of the frame member projecting into a groove-like receiving opening 22L, 22R of said insulating member such that a tight seal is formed between the frame member and the insulating member, to the extent the frame member 10 envelops the insulating member 12 and inclusive of the edges defining said openings.

More specifically, the thermal barrier, considered in cross-section through the unitary body, as arranged so that the frame member 10 overlies only part of the insulating members 12 outer periphery and is composed of two split-apart half-members 10L, 10R, each having two free ends 20L, 21L; 20 21R projecting into receiving openings 22L, 22R, 23L, 23R of the insulating member and in sealing relation therewith.

The thermal barrier 13 is essentially rectangular in cross-section, but the frame member 10 is preferably provided with flange-like projections 24L, 24R, which project beyond the rectangle, essentially parallel to that rectangular side which is formed solely by the insulating member 12. The projections facilitate attachment of the thermal barrier 13, for example, to the main metallic structure of a window frame.

Further objects of the invention, and the manner of realization of the objects of the invention, and also additional novel features of the invention, are set forth in the following, more detailed description, of which the appended claims form a part.

In FIGURES 1 and 2, which will be described first, the basic structural frame member is generally designated by 10, and the block of insulating material with which the frame 10 is united (see FIGURE 2), generally by 12. Since the members 10 and 12 are symmetrical with respect to the central axis 14, it is convenient in the description to refer to left parts by the suflix letter L, and to the right parts by suflix letter R. Only one of the parts (L or R) is explicitly described, and the description of its symmetrical part is by implication. Upon occasion, reference is made without suflix letter, and such description is intended to apply generically to the left and the right part. In this manner, needless repetition of identical verbiage is avoided.

The frame member 10 is made of a relatively thin metal (.062 inch typical), and has been prefabricated to the illustrated configuration by extrusion process. Especially for usage in window frames, the member 10 is made of aluminum; for other, related uses it may be made of steel.

The block 12 also has been prefabricated to the illustrated geometric configuration by extrusion process; materials suitable for forming the block 12 may be known rigid materials of low heat conductivity, which lend themselves well to extrusion process, such as polyvinyl chloride, polyethylene or polystyrene. The block 12 and the frame member 10 are generally prefabricated so as to be ccextensive in depth (into and out of paper), and will usually be made of uniform cross-section, namely that illustrated, even in the front and rear end surfaces (viewed into the paper). Alternatively, depending upon the particular contemplated use, the cross-section may be varied, or the end terminations may differ from cross-sections taken elsewhere, or one of the two members, 10 or 12, may be made longer than the other. Such modifications need not be described in detail.

The frame 10 and block 12 are so prefabricated as to be readily joined to be coextensive in depth by hand operation, if desired, to a moderately snug fit which may be achieved by sliding one over the other. Such preassembled form is illustrated in FIGURE 1. As illustrated in FIGURE 2, the members and 12 have been joined together so as to form a unitary structure by the action of a retractably depressible forming member 16, which for relatively long-depth frame structures may be a roller, for example, a pinch roller as will be apparent from a consideration of the subsequent drawing figures. Where the united structure, herein also referred to as the insulated frame member or the thermal barrier 13, has relatively short-depth, the forming member 16 may alternatively be a suitably shaped die or punch.

In FIGURES 3 and 4 is shown apparatus suitable for forming the thermal barrier on a continuous basis. The forming members 16 are shown as three pairs of powered rollers 16a, 16a; 16b, 16b; 16c, 160. The roller pairs may be arranged approximately four to six inches from one pair to the next pair. The rollers are affixed to suitable driving shifts 17a, 17b, 17c, which are supported for rotation by a suitable support 18, and are driven by motor drive (not shown) contained within the unit 18. Positive drive may also be imparted to the rollers 16a, 16b, 16c, or these may be simply idler rollers. The separating distance between the two rollers of a particular pair is made progressively smaller, so that separation between rollers 16a and 16a is the greatest and that between the rollers 16c and 160 the smallest. In this manner, the fracturing of the metallic extrusion member 10 and its union with the thermoplastic member 12 is gradually, but continuously accomplished.

The completed thermal barrier 13 may now be used as stock material for an insulated frame for dual primary windows. As is known in the art, such a dual primary window comprises two sash pairs, one pair of which is disposed towards the street side, and the other pair towards the room side. In each pair, at least one sash is slidable; the other may be fixed light or may also be slidable. It is in connection with such a dual primary window that the need for a thermal barrier between the two sash pairs exists; owing to the good conductivity of the metallic framework, usually aluminum framework, frosting of the room side sash pair may occur. Such frosting is avoided by provision of a thermal barrier, which is formed as a rectangular frame, co-extensive with and integrated into the overall framework for the dual primary window. Such an assembly is per se well-known in the art.

For the purposes mentioned in the preceding paragraph, the thermal barrier stock material 13 is cut to four lengths per primary window structure; they may be suitably mitered if desired. The four lengths may be united with the overall frame structure and with each other by suitable sheet metal screws as is well-known in the art.

The completed thermal barrier stock material 13, which may be typically .75 in. x .50 in. has decided advantages over thermal barriers heretofore known, among which are the following:

(1) In the construction of dual primary window, one may prepare the basic framework separately and independently of the thermal barrier, then integrate the thermal barrier to complete the frame structure. According to prior approaches, it had not been possible to dissociate the forming of the basic frame structure and that of the thermal barrier; a series of complicated steps had been required to introduce the thermoplastic insulating material into the surrounding metallic structure, which metallic structure invariably had been part of the basic framework.

(2) The completed thermal barrier stock material 13 locks the insulating material 12 rigidly in place so that the material 13 can still be handled as if it were a single piece of aluminum. In contrast, by the prior approaches, it had been necessary to provide two separate aluminum frames and then unite them with an insulating separator,

which invariably was rather loose fitting, and for this reason structurally not the best nor very efiicient as an insulator. Such prior assemblies require additional sealant; that of the present invention does not.

(3) Fewer parts are needed to complete the thermal barrier frame for a dual primary window. By use of the herein disclosed techniques, the completed stock material 13 (insulating material 12 included), merely four pieces need be cut as has been stated. According to prior techniques it had been necessary to cut eight pieces of metal and four pieces of insulating material before attempting union of these into twelve pieces with each other and with the basic overall frame structure.

From the aforegoing, it is apparent that by the present invention there has been provided, a particularly advantageous thermal barrier structure and method of making the same. The invention has been described with reference to presently preferred embodiments thereof. However, it is intended to embrace within the invention such modifications as fall within its true spirit and scope.

What is claimed is:

1. A thermal barrier comprising an elongatetd member of thermal insulating material and an elongated, relatively thin metallic frame member which overfits with sealing relation the insulating member and forms with it a unitary elongated body, the overfit being to substantial length in the longitudinal direction of the insulating member, the frame member being split apart along said longitudinal direction into a first and a second half member, each having a first free end remote from the split and a second free end in proximity to the split, the arrangement being such that considered in cross-section through the unitary body, the insulating member is generally in the shape of a rectangle having first and second parallel lateral edges and a third and a fourth side, the junctions of the first lateral edge with the third and fourth sides being hereinafter respectively referred to as the first and second end points of the first lateral edge, and the junctions of the second lateral edge with the third and fourth sides being hereinafter respectively referred to as the first and second end points of the second lateral edge, each lateral edge being provided intermediate of its first and second end points with a groove-like receiving opening hereinafter referred to as first receiving opening, and the third side being provided with two groove-like receiving openings located relatively closely to each other and hereifiafter referred to as second receiving openings, the first half members first free end projecting into the first lateral edges first receiving opening and its second free end projecting into one of the second receiving openings, and the second half members first free end projecting into the second lateral edges first receiving opening and its second free end projecting into the other second receiving opening.

2. A thermal barrier according to claim 1, wherein, considered in cross-section through said unitary body, each half-member comprises from its first free end to its second free end in order, lengths essentially having the following geometry, the insulating member being conformingly shaped: a first length disposed within the first opening and oriented generally parallel to the aforesaid third side, thence a second length flush with the aforesaid respective lateral edge to its said first end point, thence a third length flush with the aforesaid third side, thence a fourth length fiush with a conforming edge of the insulating body which fourth length extends from the end point of the third length obliquely towards intersection with the fourth length of the other half-member at a point located inside the rectangle, and thence a fifth length extending once more toward the respective lateral edge.

3. A thermal barrier according to claim 2, wherein, considered in cross-section through said unitary body, each fifth length is arcuate in shape.

4. A thermal barrier according to claim 2, wherein, considered in cross-section through said unitary body, each fifth length is in the shape of a circular arc.

5. A thermal barrier according to claim 2, wherein, considered in cross-section through said unitary body, each third length projects laterally outwardly in flangelike fashion, beyond its respective first end point of the respective lateral edge.

6. A thermal barrier according to claim 1, wherein the frame member is made of aluminum.

7. A thermal barrier according to claim 1, wherein the frame member is made of steel.

'8. A thermal barrier according to claim 1, wherein the insulating member is made of rigid insulating material References Cited UNITED STATES PATENTS 6/1939 Blessin 52397 X 6/ 1940 Schunk 52398 X 12/1963 Briggs 52-627 X 11/1964 Cameron 52-403 FOREIGN PATENTS 1961 Switzerland.

JOHN E. MURTAGH, Primary Examiner.

US Cl. X.R.

selected from the group consisting of polyvinyl chloride, 15 52732 polyethylene, polystyrene. 

